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-rw-r--r--lib/curl_setup.h15
-rw-r--r--lib/sendf.c102
-rw-r--r--lib/url.c46
-rw-r--r--lib/urldata.h17
4 files changed, 179 insertions, 1 deletions
diff --git a/lib/curl_setup.h b/lib/curl_setup.h
index da26e48cb..d78873fe5 100644
--- a/lib/curl_setup.h
+++ b/lib/curl_setup.h
@@ -722,4 +722,19 @@ endings either CRLF or LF so 't' is appropriate.
#define FOPEN_WRITETEXT "w"
#endif
+/* WinSock destroys recv() buffer when send() failed.
+ * Enabled automatically for Windows and for Cygwin as Cygwin sockets are
+ * wrappers for WinSock sockets. https://github.com/curl/curl/issues/657
+ * Define DONT_USE_RECV_BEFORE_SEND_WORKAROUND to force disable workaround.
+ */
+#if !defined(DONT_USE_RECV_BEFORE_SEND_WORKAROUND)
+# if defined(WIN32) || defined(__CYGWIN__)
+# define USE_RECV_BEFORE_SEND_WORKAROUND
+# endif
+#else /* DONT_USE_RECV_BEFORE_SEND_WORKAROUNDS */
+# ifdef USE_RECV_BEFORE_SEND_WORKAROUND
+# undef USE_RECV_BEFORE_SEND_WORKAROUND
+# endif
+#endif /* DONT_USE_RECV_BEFORE_SEND_WORKAROUNDS */
+
#endif /* HEADER_CURL_SETUP_H */
diff --git a/lib/sendf.c b/lib/sendf.c
index a75c5c743..23bcfa2c9 100644
--- a/lib/sendf.c
+++ b/lib/sendf.c
@@ -33,6 +33,7 @@
#include "non-ascii.h"
#include "curl_printf.h"
#include "strerror.h"
+#include "select.h"
/* The last #include files should be: */
#include "curl_memory.h"
@@ -120,6 +121,90 @@ static size_t convert_lineends(struct SessionHandle *data,
}
#endif /* CURL_DO_LINEEND_CONV */
+#ifdef USE_RECV_BEFORE_SEND_WORKAROUND
+static void pre_receive_plain(struct connectdata *conn, int num)
+{
+ const curl_socket_t sockfd = conn->sock[num];
+ struct postponed_data * const psnd = &(conn->postponed[num]);
+ size_t bytestorecv = psnd->allocated_size - psnd->recv_size;
+ /* WinSock will destroy unread received data if send() is
+ failed.
+ To avoid lossage of received data, recv() must be
+ performed before every send() if any incoming data is
+ available. However, skip this, if buffer is already full. */
+ if((conn->handler->protocol&PROTO_FAMILY_HTTP) != 0 &&
+ conn->recv[num] == Curl_recv_plain &&
+ (!psnd->buffer || bytestorecv)) {
+ const int readymask = Curl_socket_check(sockfd, CURL_SOCKET_BAD,
+ CURL_SOCKET_BAD, 0);
+ if(readymask != -1 && (readymask & CURL_CSELECT_IN) != 0) {
+ /* Have some incoming data */
+ if(!psnd->buffer) {
+ /* Use buffer double default size for intermediate buffer */
+ psnd->allocated_size = 2 * BUFSIZE;
+ psnd->buffer = malloc(psnd->allocated_size);
+ psnd->recv_size = 0;
+ psnd->recv_processed = 0;
+#ifdef DEBUGBUILD
+ psnd->bindsock = sockfd; /* Used only for DEBUGASSERT */
+#endif /* DEBUGBUILD */
+ bytestorecv = psnd->allocated_size;
+ }
+ if(psnd->buffer) {
+ ssize_t recvedbytes;
+ DEBUGASSERT(psnd->bindsock == sockfd);
+ recvedbytes = sread(sockfd, psnd->buffer + psnd->recv_size,
+ bytestorecv);
+ if(recvedbytes > 0)
+ psnd->recv_size += recvedbytes;
+ }
+ else
+ psnd->allocated_size = 0;
+ }
+ }
+}
+
+static ssize_t get_pre_recved(struct connectdata *conn, int num, char *buf,
+ size_t len)
+{
+ struct postponed_data * const psnd = &(conn->postponed[num]);
+ size_t copysize;
+ if(!psnd->buffer)
+ return 0;
+
+ DEBUGASSERT(psnd->allocated_size > 0);
+ DEBUGASSERT(psnd->recv_size <= psnd->allocated_size);
+ DEBUGASSERT(psnd->recv_processed <= psnd->recv_size);
+ /* Check and process data that already received and storied in internal
+ intermediate buffer */
+ if(psnd->recv_size > psnd->recv_processed) {
+ DEBUGASSERT(psnd->bindsock == conn->sock[num]);
+ copysize = CURLMIN(len, psnd->recv_size - psnd->recv_processed);
+ memcpy(buf, psnd->buffer + psnd->recv_processed, copysize);
+ psnd->recv_processed += copysize;
+ }
+ else
+ copysize = 0; /* buffer was allocated, but nothing was received */
+
+ /* Free intermediate buffer if it has no unprocessed data */
+ if(psnd->recv_processed == psnd->recv_size) {
+ free(psnd->buffer);
+ psnd->buffer = NULL;
+ psnd->allocated_size = 0;
+ psnd->recv_size = 0;
+ psnd->recv_processed = 0;
+#ifdef DEBUGBUILD
+ psnd->bindsock = CURL_SOCKET_BAD;
+#endif /* DEBUGBUILD */
+ }
+ return (ssize_t)copysize;
+}
+#else /* ! USE_RECV_BEFORE_SEND_WORKAROUND */
+/* Use "do-nothing" macros instead of functions when workaround not used */
+#define pre_receive_plain(c,n) do {} WHILE_FALSE
+#define get_pre_recved(c,n,b,l) 0
+#endif /* ! USE_RECV_BEFORE_SEND_WORKAROUND */
+
/* Curl_infof() is for info message along the way */
void Curl_infof(struct SessionHandle *data, const char *fmt, ...)
@@ -255,6 +340,12 @@ ssize_t Curl_send_plain(struct connectdata *conn, int num,
{
curl_socket_t sockfd = conn->sock[num];
ssize_t bytes_written;
+ /* WinSock will destroy unread received data if send() is
+ failed.
+ To avoid lossage of received data, recv() must be
+ performed before every send() if any incoming data is
+ available. */
+ pre_receive_plain(conn, num);
#ifdef MSG_FASTOPEN /* Linux */
if(conn->bits.tcp_fastopen) {
@@ -322,7 +413,16 @@ ssize_t Curl_recv_plain(struct connectdata *conn, int num, char *buf,
size_t len, CURLcode *code)
{
curl_socket_t sockfd = conn->sock[num];
- ssize_t nread = sread(sockfd, buf, len);
+ ssize_t nread;
+ /* Check and return data that already received and storied in internal
+ intermediate buffer */
+ nread = get_pre_recved(conn, num, buf, len);
+ if(nread > 0) {
+ *code = CURLE_OK;
+ return nread;
+ }
+
+ nread = sread(sockfd, buf, len);
*code = CURLE_OK;
if(-1 == nread) {
diff --git a/lib/url.c b/lib/url.c
index f1028f34c..184e27049 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -2694,6 +2694,43 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option,
return result;
}
+#ifdef USE_RECV_BEFORE_SEND_WORKAROUND
+static void conn_reset_postponed_data(struct connectdata *conn, int num)
+{
+ struct postponed_data * const psnd = &(conn->postponed[num]);
+ if(psnd->buffer) {
+ DEBUGASSERT(psnd->allocated_size > 0);
+ DEBUGASSERT(psnd->recv_size <= psnd->allocated_size);
+ DEBUGASSERT(psnd->recv_processed < psnd->recv_size);
+ DEBUGASSERT(psnd->bindsock != CURL_SOCKET_BAD);
+ free(psnd->buffer);
+ psnd->buffer = NULL;
+ psnd->allocated_size = 0;
+ psnd->recv_size = 0;
+ psnd->recv_processed = 0;
+#ifdef DEBUGBUILD
+ psnd->bindsock = CURL_SOCKET_BAD; /* used only for DEBUGASSERT */
+#endif /* DEBUGBUILD */
+ }
+ else {
+ DEBUGASSERT (psnd->allocated_size == 0);
+ DEBUGASSERT (psnd->recv_size == 0);
+ DEBUGASSERT (psnd->recv_processed == 0);
+ DEBUGASSERT (psnd->bindsock == CURL_SOCKET_BAD);
+ }
+}
+
+static void conn_reset_all_postponed_data(struct connectdata *conn)
+{
+ conn_reset_postponed_data(conn, 0);
+ conn_reset_postponed_data(conn, 1);
+}
+#else /* ! USE_RECV_BEFORE_SEND_WORKAROUND */
+/* Use "do-nothing" macros instead of functions when workaround not used */
+#define conn_reset_postponed_data(c,n) do {} WHILE_FALSE
+#define conn_reset_all_postponed_data(c) do {} WHILE_FALSE
+#endif /* ! USE_RECV_BEFORE_SEND_WORKAROUND */
+
static void conn_free(struct connectdata *conn)
{
if(!conn)
@@ -2744,6 +2781,8 @@ static void conn_free(struct connectdata *conn)
Curl_safefree(conn->proxy.rawalloc); /* proxy name buffer */
Curl_safefree(conn->master_buffer);
+ conn_reset_all_postponed_data(conn);
+
Curl_llist_destroy(conn->send_pipe, NULL);
Curl_llist_destroy(conn->recv_pipe, NULL);
@@ -3851,6 +3890,10 @@ static struct connectdata *allocate_conn(struct SessionHandle *data)
conn->connection_id = -1; /* no ID */
conn->port = -1; /* unknown at this point */
conn->remote_port = -1; /* unknown */
+#if defined(USE_RECV_BEFORE_SEND_WORKAROUND) && defined(DEBUGBUILD)
+ conn->postponed[0].bindsock = CURL_SOCKET_BAD; /* no file descriptor */
+ conn->postponed[1].bindsock = CURL_SOCKET_BAD; /* no file descriptor */
+#endif /* USE_RECV_BEFORE_SEND_WORKAROUND && DEBUGBUILD */
/* Default protocol-independent behavior doesn't support persistent
connections, so we set this to force-close. Protocols that support
@@ -5625,6 +5668,9 @@ static void reuse_conn(struct connectdata *old_conn,
/* persist connection info in session handle */
Curl_persistconninfo(conn);
+ conn_reset_all_postponed_data(old_conn); /* free buffers */
+ conn_reset_all_postponed_data(conn); /* reset unprocessed data */
+
/* re-use init */
conn->bits.reuse = TRUE; /* yes, we're re-using here */
diff --git a/lib/urldata.h b/lib/urldata.h
index 016761929..f190fbdd6 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -833,6 +833,20 @@ typedef ssize_t (Curl_recv)(struct connectdata *conn, /* connection data */
size_t len, /* max amount to read */
CURLcode *err); /* error to return */
+#ifdef USE_RECV_BEFORE_SEND_WORKAROUND
+struct postponed_data {
+ char *buffer; /* Temporal store for received data during
+ sending, must be freed */
+ size_t allocated_size; /* Size of temporal store */
+ size_t recv_size; /* Size of received data during sending */
+ size_t recv_processed; /* Size of processed part of postponed data */
+#ifdef DEBUGBUILD
+ curl_socket_t bindsock;/* Structure must be bound to specific socket,
+ used only for DEBUGASSERT */
+#endif /* DEBUGBUILD */
+};
+#endif /* USE_RECV_BEFORE_SEND_WORKAROUND */
+
/*
* The connectdata struct contains all fields and variables that should be
* unique for an entire connection.
@@ -931,6 +945,9 @@ struct connectdata {
Curl_recv *recv[2];
Curl_send *send[2];
+#ifdef USE_RECV_BEFORE_SEND_WORKAROUND
+ struct postponed_data postponed[2]; /* two buffers for two sockets */
+#endif /* USE_RECV_BEFORE_SEND_WORKAROUND */
struct ssl_connect_data ssl[2]; /* this is for ssl-stuff */
struct ssl_config_data ssl_config;
bool tls_upgraded;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-04 21:52:51 +0000